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Alphabetical listing for C

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ctermid(3)
NAME
  ctermid - Generate the pathname for the controlling terminal

SYNOPSIS
  #include <stdio.h>

  char *ctermid(
	  char *s );

LIBRARY
  Standard C Library (libc)

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  ctermid():  XPG4, XPG4-UNIX

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  s   Points to the array into which the ctermid() function copies the string
      representing the pathname.

DESCRIPTION
  The ctermid() function generates a string that, when used as a pathname,
  refers to the current controlling terminal for the current process. If
  ctermid() returns a pathname, access to the file is not guaranteed.

  The ctermid() function differs from the ttyname() function in that the
  ttyname() function is supplied a file descriptor and returns the actual
  name of the terminal associated with that file descriptor, while the
  ctermid() function returns a string (/dev/tty) that refers to the terminal
  if used as a filename. Thus, the ttyname() function is useful only if the
  process already has at least one file open to a terminal.

RETURN VALUES
  If the s parameter is not a null pointer, it points to a character array of
  at least L_ctermid bytes.  The pathname is placed in this array and the
  value of the s parameter is returned. The symbolic constant L_ctermid is
  defined in the stdio.h header file, and has a value greater than 0 (zero).

  If the s parameter is a null pointer, the string is stored in an internal
  static area and the address is returned. The next call to the ctermid()
  function overwrites the contents of the internal static area.

  If the pathname that would refer to the controlling terminal cannot be
  determined, or if the function is unsuccessful, the ctermid() function
  returns an empty string.

SEE ALSO
  Functions: ttyname(3)

  Standards: standards(5)

Index for Section 3

Alphabetical listing for C

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